Invalid sling



FIG. 1 is a top plan view of an invalid sling showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a perspective view showing the invalid sling in use;

FIG. 4 is a front elevational view of the invalid sling;

FIG. 5 is a left elevational view thereof;

FIG. 6 is a right elevational view thereof; and,

FIG. 7 is a rear elevational view thereof.

The broken line showing is for illustrative purposes only and forms nopart of the claimed design.

The ornamental design for an invalid sling, as shown and described.